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ARLApplied Research Laboratories The University of Texas at Austin
ARLApplied Research Laboratories The University of Texas at Austin
Ionospheric Tomography Network of Egypt
T W GarnerApplied Research Laboratories
University of Texas at Austin
A M MahrousSpace Weather Monitoring Center
Helwan University
ARLApplied Research Laboratories The University of Texas at Austin
Ionospheric Tomography Network of Egypt
•Chain of 3 CIDRs in Egypt as part of ISWI• Only 1 is operational right
now•Located at different university campuses across Egypt.•Operated jointly by Helwan University (Ayman Mahrous) and ARL:UT (Trevor Garner)
ARLApplied Research Laboratories The University of Texas at Austin
UHF/VHF Satellite Radio Beacons
Transit- First satellite navigation system Satellites in LEO (~1000 km), polar orbit Transmitted navigation message at 150 and 400 MHz Doppler shift of the signals used for positioning Decommissioned in 1989 to the Navy Ionospheric Monitoring
System (NIMS) 4 Active beacons
Other US Radio Beacons- Several DoD missions have flown a NRL-developed radio
beacon C/NOFS, DMSP F15, Radcal
Several other nations have flown or will fly radio beacons COSMIC, ePoP, future Brazilian and Indian missions
Coherent Ionospheric Doppler Receivers (CIDRs)
Designed to track 150/400MHz LEO beacons (Transit/NIMS, GFO)
Provides relative TEC and phase scintillation measurements
Useful for examining spatial structure with a relatively sparse receiver network and conducting ionospheric tomography
30 meter RF cable
150 MHz
400 MHz PCRX
ARLApplied Research Laboratories The University of Texas at Austin
CIDR measurements
Doppler shift in both the 150 and 400 MHz channels
Linear combinations of these two Doppler shifts produce three separate ionospheric measurements STEC/t Ionospheric δf at 150 MHz Ionospheric δf at 400 MHz
The STEC/t can be integrated to a STEC under the satellite
All three measurements can be binned and RMS values used to characterize the scintillation
ARLApplied Research Laboratories The University of Texas at Austin
Ionospheric Doppler Shift
ARLApplied Research Laboratories The University of Texas at Austin
Dual Frequency Combinations
Most existing UHF/VHF beacons transmit at 8/3
There are 2 basic linear combinations for dual frequency Doppler measurements
ARLApplied Research Laboratories The University of Texas at Austin
Scale of CIDR measurements
For a typical beacon satellite orbit, the satellite crosses a full field of view in 20 minutes. Corresponds to an arc distance of ~0.15o in 1 second
The CIDR are sensitive to smaller-scale structures At 1 Hz: F-region structures (300 km) ~1570 m E-region structures (100 km) ~525 m Limited by the Fresnel Scale
F-region Fresnel Scale ~ 774.5 m E-region Fresnel Scale ~ 447.2 m
ARLApplied Research Laboratories The University of Texas at Austin
Features of UHF/VHF Beacon Electron Content Measurements
Spacecraft cross the field of view in ~20 min (GPS spacecraft take ~8hrs) Enable tomographic reconstruction
Measurements from LEO spacecraft (~1000 km) Purely ionospheric measurement
Shorter frequencies (400 MHz vrs 1575.42 MHz) More precise TEC measurements
TEC ~ /f2
CIDR ~ 15.5 more precise than GPS
ARLApplied Research Laboratories The University of Texas at Austin
More Differences Between GPS and CIDRs
Tend to have a higher data rates 1 kHz decimated to 1-10 Hz Allows measurements of the rapid ionospheric
variations Relative TEC measurements
Relative to an unknown integration constant GPS TEC relative unknown transmitter and receiver
biases
ARLApplied Research Laboratories The University of Texas at Austin
CIDR Data Chain
Receiver records the raw Doppler measurements
Postprocessing code quality checks the Doppler measurements, calculates the positioning solutions, and converts the Doppler measurements to TEC/t and TEC
Sample Doppler File# 26 29.8643 31.317 80.83# 19071 885 10 Operational 1# 2008 299 17 33 36.000000# 2008 299 17 48 21.00000063216.197 10.0637 7.10131 97.65 97.522 26.8365 42.4497 97.694 98.12763217.197 10.0658 7.10073 97.426 97.479 26.8422 42.4422 97.581 97.83263218.197 10.068 7.10085 97.878 97.812 26.8479 42.3683 97.691 97.2463219.197 10.0701 7.27558 97.557 97.389 26.8536 41.9037 97.653 98.37363220.197 10.0722 7.93775 98.103 98.189 26.8593 40.1246 97.446 97.38763221.197 10.0744 8.10001 97.438 98.372 26.865 37.942 98.407 97.11663222.197 10.0765 8.16741 97.466 97.797 26.8708 35.6967 97.718 97.8663223.197 10.0787 8.24624 98.141 97.949 26.8766 33.393 97.701 96.81363224.197 10.0809 8.32116 98.04 97.6 26.8824 31.644 97.529 98.16563225.197 10.0831 8.39498 98.114 98.024 26.8882 31.3944 97.263 97.76563226.197 10.0852 8.46514 97.797 97.8 26.894 31.223 97.798 97.52663227.197 10.0875 8.54308 97.436 98.121 26.8999 31.0545 98.33 97.99863228.197 10.0897 8.62002 97.748 96.938 26.9058 30.8809 97.919 98.10863229.197 10.0919 8.70217 98.113 97.25 26.9117 30.7075 97.743 97.56863230.197 10.0941 8.77954 97.852 98.082 26.9176 30.5294 97.082 98.00463231.197 10.0963 8.85599 97.782 97.569 26.9235 30.3477 97.384 97.83963232.197 10.0986 8.92959 98.008 98.518 26.9295 30.1655 97.244 97.61163233.197 10.1008 9.00296 97.701 97.969 26.9355 30.0031 98.074 97.47763234.197 10.1031 9.08251 98.255 96.871 26.9415 29.8274 97.158 97.81263235.197 10.1053 9.16268 97.102 98.323 26.9475 29.6476 97.737 98.14363236.197 10.1076 9.23541 97.405 98.081 26.9536 29.4676 97.753 97.74263237.197 10.1099 9.31232 97.269 97.461 26.9597 29.2921 97.727 97.91163238.197 10.1122 9.38987 97.557 97.733 26.9658 29.1236 97.734 97.07663239.197 10.1145 9.46732 97.843 98.639 26.9719 28.9631 96.98 97.191
Sample Processed Text File# GLOBAL ATTRIBUTES -- name : valueCONTACT : Trevor Garner, ARL:UT, [email protected] : Kanish MehtaSOURCE : Applied Research Laboratories: University of Texas at Austininstrument : ARL:UT CIDR Receiver # 26receiver_location : Helwanreceiver_latitude : 29.8643receiver_longitude : 31.317receiver_altitude : 80.83sample_rate_hz : 1satellite_name : OSCAR 32 num_data : 643
# UT Relative TEC Rate Sat.Lat Sat.Lon Sat.Alt Azimuth Elevation F Lat F Long E Lat E Lon Phase Rate Phase Rate Sat.Vel Good# (sec) TEC (TECU) (TECU/1.00s) (deg) (deg) (km) (deg) (deg) (deg) (deg) (deg) (deg) VHF (Hz) UHF (Hz) (km/s) Flag63278.2 3.0654 -0.0308161 52.2703 61.5188 1299.31 36.0752 2.37675 41.4956 43.0712 35.797 36.7374 10.6 27.5 20.5309 163279.2 3.07675 0.0113533 52.217 61.514 1299.23 36.1573 2.4098 41.4602 43.0659 35.7708 36.7281 10.2 27.5 20.6618 163280.2 3.07026 -0.00648761 52.1636 61.5092 1299.16 36.2396 2.44283 41.4248 43.0606 35.7447 36.7189 10.4 27.5 20.5964 163281.2 3.07675 0.00648761 52.1103 61.5044 1299.09 36.322 2.47583 41.3895 43.0553 35.7187 36.7097 10.3 27.7 20.8036 163282.2 3.04269 -0.0340599 52.0569 61.4996 1299.01 36.4045 2.50881 41.3542 43.05 35.6928 36.7005 10.5 27.4 20.4764 163283.2 3.04755 0.00486571 52.0036 61.4948 1298.94 36.4872 2.54178 41.319 43.0447 35.6671 36.6914 10.3 27.4 20.5418 163284.2 3.03458 -0.0129752 51.9502 61.4901 1298.86 36.5701 2.57472 41.2839 43.0394 35.6414 36.6823 10.4 27.4 20.5091 163285.2 3.05242 0.0178409 51.8969 61.4853 1298.79 36.6531 2.60763 41.2489 43.0341 35.6159 36.6732 10.2 27.5 20.6618 163286.2 3.04431 -0.00810951 51.8435 61.4805 1298.71 36.7362 2.64053 41.2139 43.0288 35.5904 36.6642 10.4 27.5 20.5964 163287.2 3.0362 -0.00810951 51.7902 61.4757 1298.64 36.8195 2.6734 41.1789 43.0236 35.5651 36.6552 10.4 27.5 20.5964 163288.2 3.04593 0.00973141 51.7368 61.4709 1298.56 36.9029 2.70625 41.1441 43.0183 35.5399 36.6462 10.2 27.5 20.6618 163289.2 3.02971 -0.016219 51.6835 61.4662 1298.49 36.9865 2.73908 41.1092 43.0131 35.5148 36.6373 10.4 27.4 20.5091 163290.2 3.02323 -0.00648761 51.6301 61.4614 1298.41 37.0702 2.77188 41.0745 43.0079 35.4898 36.6285 10.4 27.5 20.5964 163291.2 3.0216 -0.0016219 51.5768 61.4566 1298.34 37.1541 2.80466 41.0398 43.0026 35.465 36.6196 10.3 27.5 20.6291 163292.2 3.02971 0.00810951 51.5234 61.4518 1298.26 37.2381 2.83741 41.0052 42.9974 35.4402 36.6108 10.2 27.5 20.6618 1 63293.2 3.0216 -0.00810951 51.4701 61.4471 1298.18 37.3223 2.87015 40.9706 42.9922 35.4155 36.602 10.4 27.5 20.5964 163294.2 3.00538 -0.016219 51.4167 61.4423 1298.11 37.4066 2.90285 40.9362 42.9871 35.391 36.5933 10.4 27.4 20.5091 163295.2 2.99565 -0.00973141 51.3633 61.4375 1298.03 37.491 2.93553 40.9017 42.9819 35.3665 36.5846 10.4 27.6 20.6836 163296.2 2.9989 0.0032438 51.31 61.4328 1297.96 37.5757 2.96819 40.8674 42.9767 35.3422 36.576 10.2 27.3 20.4873 163297.2 2.98268 -0.016219 51.2566 61.428 1297.88 37.6604 3.00082 40.8331 42.9716 35.318 36.5674 10.4 27.4 20.5091 163298.2 2.96808 -0.0145971 51.2033 61.4232 1297.8 37.7453 3.03343 40.7988 42.9664 35.2938 36.5588 10.4 27.4 20.5091 163299.2 2.95511 -0.0129752 51.1499 61.4185 1297.73 37.8304 3.06601 40.7646 42.9613 35.2698 36.5503 10.4 27.4 20.5091 163300.2 2.94862 -0.00648761 51.0965 61.4137 1297.65 37.9156 3.09856 40.7305 42.9562 35.2459 36.5418 10.3 27.4 20.5418 163301.2 2.93564 -0.0129752 51.0432 61.4089 1297.57 38.0009 3.13109 40.6965 42.9511 35.2221 36.5333 10.4 27.5 20.5964 163302.2 2.92916 -0.00648761 50.9898 61.4042 1297.5 38.0864 3.1636 40.6625 42.946 35.1984 36.5249 10.3 27.4 20.5418 163303.2 2.91131 -0.0178409 50.9364 61.3994 1297.42 38.1721 3.19607 40.6285 42.9409 35.1748 36.5165 10.4 27.3 20.4218 163304.2 2.90483 -0.00648761 50.883 61.3947 1297.34 38.2579 3.22852 40.5947 42.9358 35.1513 36.5081 10.3 27.3 20.4545 163305.2 2.89672 -0.00810951 50.8297 61.3899 1297.26 38.3438 3.26094 40.5609 42.9308 35.1279 36.4998 10.3 27.3 20.4545 1
ARLApplied Research Laboratories The University of Texas at Austin
Sample ITNE Observation
ARLApplied Research Laboratories The University of Texas at Austin
ITNE Science Goals
Large-scale plasma structures Chain is located underneath of equatorial fountain peaks
(15.6 to 23.8 deg magnetic latitude) Routine observations of the equatorial fountain peaks Tomography and data assimilative reconstructions of the
fountain Small-scale plasma irregularities
TEC variations associated with equatorial anomaly peaks Examine the consequence with tropospheric weather
Comparison with the American sector CIDR chain Examine the impact of greater geographic/magnetic latitude
offsets in the Americas
ARLApplied Research Laboratories The University of Texas at Austin
Analysis of Sample Observation
Ionospheric Tomography
Traditional usage of the CIDR-like measurements Utilizes crossing ray paths
Typically 3-5 receivers along aligned with the orbit
Assumes a slowly varying ionosphere Typically 15 minute time steps
ARLApplied Research Laboratories The University of Texas at Austin
Contact Information
If you are interested in working with ITNE data, please contact: Ayman Mahrous ([email protected]) Trevor Garner ([email protected])
ARLApplied Research Laboratories The University of Texas at Austin
Summary
First ITNE CIDR is up and running First results of Coherent Ionospheric Doppler Receiver
measurements over Egypt, Mahrous, A., A. Shimeis, and T. Garner, Space Weather, 8, doi:10.1029/2009SW000548, 2010.
Excellent opportunity to study the northern crest of equatorial fountain in Africa
Please contact [email protected] or [email protected] if you think ITNE data can help in your data study.